Xbox one s powers on then off after about 3 seconds - no fan spin at all

I have just got an xbox one s mobo - according to seller it powered up but had garbled display.
When I powered it up (or tried) there was no fan spin at all - it stayed on for about 3-4 seconds and then turned off.

I have tried several different fans with no difference - and cannot find any shorts anything else wrong on the board.

Anyone have any ideas?

Kr
FD

On then off problems on a XB one system indicates issues with GPU/Southbridge chip not a fan issue. Without the proper tools to re-ball the chips the board is pretty much done. Sorry.